1. Field
The present invention relates to a chip-type electric double layer capacitor, and more particularly, to a chip-type electric double layer capacitor effectively preventing an electrolyte spill.
2. Description of the Related Art
In various electronic products such as information communication devices, a stable energy supply is considered to be an important element. In general, such a function is performed by a capacitor. That is, the capacitor serves to store electricity in a circuit provided in various electronic products such as information communication devices and then discharge the electricity, thereby stabilizing the flow of electricity within the circuit.
In recent years, a great deal of attention has been paid to an electric double layer capacitor as a product satisfying the requirements of functions that are not served by a conventional condenser or secondary cell, since the electric double layer capacitor has a short charge and discharge time and high output density.
In general, an electric double layer capacitor has intermediate properties between those of a condenser and those of a secondary cell in terms of energy density, output density and charge and discharge cycles.
Unlike a condenser and a secondary cell, an electric double layer capacitor has the advantages of: a simplified electrical circuit and reduced unit cost since overcharge and overdischarge may be avoided; the detection of remaining capacitance by the measuring of voltage; durability within a wide temperature range (−30° C. to +90° C.).; the use of environmentally friendly materials and so on.
An electric double layer capacitor is being utilized as a power source for the backup of home appliances such as cellphones, AVs or cameras, and is expected to be mainly utilized in UPS or HEV/FCEV applications in the future. Particularly, studies are being carried out in order to utilize an electric double layer capacitor as a power source for the ignition and acceleration of a car since the electric double layer capacitor has a life cycle equivalent to that of the lifespan of a car and high output characteristics.
A basic structure of the electric double layer capacitor includes an electrode, an electrolyte, a current collector, and a separator. The electrode has a relatively large surface area, such as that of a porous electrode. The operational principle of the electric double layer capacitor is an electro-chemical mechanism in which electricity is generated when a voltage of several volts is applied to both ends of a unit cell electrode such that ions in the electrolyte move along an electric field to be adsorbed by an electrode surface.
In order to surface mount such an electric double layer capacitor on a circuit board, a bracket is welded over and under the electric double layer capacitor, and the electric double layer capacitor is then mounted on the circuit board through the bracket.
However, the electric double layer capacitor having such a structure may have an increase in thickness due to additional structures required for surface mounting. Also, when an exterior case is used, an electrolyte spill in a vulnerable area of the exterior case during subsequent processes (aging, soldering reflow, or the like) may be caused, and thus the reliability and lifespan of a chip-type electric double layer capacitor may be reduced.